Drain valve mechanism



March 28, 1944. w. B. KIRK DRAIN VALVE MECHANISM Filed July 30, 1942ATTORNEY Patented Mar. 28, 1944 DRAIN VALVE MECHANISM Walter B. Kirk,East McKeesport, Pa., assigner to The Westinghouse Air Brake Company,Wilmerding, Pa., a corporation of Pennsylvania Application July 30,1942, Serial N0. 452,882

Claims.

This invention relates to drain valve mechanism for dischargingcondensate from uid pressure storage reservoirs, and more particularlyto an automatically timed drain valve apparatus operative atpredetermined intervals.

In order to insure proper drainage of condensed lmoisture from thereceiving reservoirs of a, compressed air system, such as the mainreservoirs and aftercoolers associated with an air lbrake system on alocomotive, it has been-proposed to equip such a reservoir with a fluidpressure actuated drain valve device, together with means for effectingintermittent operation of the drain valve device in accordance withvariations in :pressure in a brake cylinder, or in response to operationof a compressor governor. While such means for controlling a drain valvemechanism have been employed with success in certain classes of railwayservice, there is nevertheless a need for means effecting periodicoperation of a drain valve at predetermined intervals of time,regardless of the operationr of the associated brake system or pumpgovernor device.

'I'he principal object of my invention is to provide an improved drainvalve equipment including means for effecting periodic discharge ofAcondensate from a reservoir at regular intervals.

Other objects and advantages of the invention will appear in thefollowing more detailed description thereof, taken in connection withthe accompanying drawing, in which the single gure represents indiagrammatic form the several elements, shown partly in section, of anautomatic drain valve mechanism constructed in accordance with theinvention.

The equipment illustrated in schematic form in the drawing comprises amain'reservoir I, which is adapted to be charged with compressed air bymeans of a suitable compressor, not shown, and which has associatedtherewith a fluid pressure actuated drain valve device 2, a timingreservoir 3 and a timing valve device 4. It will be understood that inactual practice the drain valve device and timing valve device may beassociated with more than one main reservoir, or with an aftercooler orthe like, depending upon the equipment carried by the locomotive.

The drain valve device 2 comprises a casing y tube I0. Formed in thecasing section 5 is a con.- densate collecting chamber I2 whichcommunicates by way of a passage I3 with the interior of the mainreservoir I. A bore I4 connects the chamber I 2 with a valve chamber I5,also formed in the casing section and communicating by way of a bore I6with the chamber 9. A double valve element I8 disposed within the valvechamber I5 is engageable with a seat I9 for controlling communicationbetween the chambers I2 and I5, or alternatively with a valve seat forcontrolling communication between chambers I5 and I 9. The double valveelement I8 is supported through the medium of the fluted stem 23slidably tting the bore I4, and a similar stem 24 slidably mounted inthe other bore I 6, it being noted that the valve element and stems areinclined in alignment with the axis of the canted diaphragm 1. The utedstem 24 operatively engages a follower member 25 which is attached tothe diaphragm 1, and which is subject to the force exerted by a coilspring 26 interposed between the follower element and an upper wall ofthe chamber 9. The spring 26 normally urges diaphragm 1 downwardly andinto engagement with a stop portion 21 of the casing. A coil spring 28is interposed between the uted stem 23 and an upper wall of the chamberI2 for urging the double valve element I8 downwardly vinto engagementwith the seat 20, as shown in the drawing, in which position of thevalve element communication is maintained between the chamber I5 andchamber I2.

The timing valve device 4 comprises a cylindrical lcasing 30 having anend wall 3|, a closure member 32 having screw-threaded connection withthe open end of the casing, and a piston valve element 34 which isslidably mounted in a bore 35 formed in the cylindrical casing. Alchamber 36 is formed between the valve piston 34 and the end wall 3 Iwhich chamber communicates by Way of passages 31 and a pipe 38 with .thelowermost portion of the timing reservoir 3. The valve piston 34 carriesa sealing gasket 39 which is adapted to engage an annular seat rib 40formed on the wall 3I for cutting oi communication between the timingreservoir 3 and the chamber 36. A coil spring 43 is interposed betweenthe valve piston 34 and the closure member 32 for urging the valvepiston into seated position as shown in the drawing. The referencecharacter 45 designates the chamber within which the spring 43 isdisposed, vwhich chamber communicates with the atmosphere through apassage 46 in the closuremember, and is also normally in communicationlby way of a port 41,

passage 49 and pipe 48 with the chamber 8 of the drain valve device 2. Asealing rib 50 carried on the end of the valve piston 34 is adapted toengage a gasket 5I, carried in the closure member,vupon movement of thevalve piston 34 away from the seat rib 40, as hereinafter explained.

The valve piston 34 is also constructed and arranged to controlcommunication between the chamber 36 and pipe 48 by Way of a port 53,which is formed in the casing 30 and is adapted to be uncovered by thevalve piston upon movementto its right-hand position. The apparatus isarranged to permit drainage of any condensate deposited in the timingreservoir 3, from which the iluid can flow downwardly by way of the pipe38, chamber 36, port 53 and pipe 48 to a' discharge pipe 55, whichcommunicates with the atmosphere by way of a restricted opening 56.

An always open communication is provided for connecting the mainreservoir I and the timing reservoir 3, comprising a pipe 58 havinginterposed therein an air strainer device 59 of suitable construction,and a choke fitting having a restricted passaged 60 for limiting therate of flow of compressed air to the timing reservoir. In operation,air supplied under pressure to the main reservoir I flows therefrom byway of the pipe 58 to the timing reservoir 3 at a rate.

the entire pressure area of the piston valve ele- 1 ment, whichthereupon forced to its right-hand position, with the rib 58 inengagement with the gasket 5I. In so moving, the piston valve element 34uncovers the port 53, through which compressed air flows from thechamber 35 to the pipe 48 and thence to the chamber 8 of the drain valvedevice 2. It will be understood that although air under pressuremeanwhile is gradually vented from the pipe 48 to atmosphere by way ofthe restricted passage 56, the rate of such venting is so controlled asto permit the initial increase in fluid pressure in the chamber 8necessary to effect operation of the drain valve device. y A

The pressure of air thus supplied to the pressure chamber 8 operates thediaphragm 1, Vfollower member 25, and stem 24 to shift the dou-'- blevalve element I8 away from the lower seat 20 and into'engagement withthe upper seat I9, in opposition to the combined forces of the springs26 and 28. As the double valve element I8 traverses the distance betweenthe two seats, the pressure of air contained in the main reservoir Iacts' againstthe water which has accumulated inthe chambers I2 and I5 toeffect quick discharge thereof, the condensate being driven out past theseat 20 and through the chamber 9 and drainage tube I0. It will beunderstood that movement of the double valve element I8 into engagementwith the upper seat I9 is accomplished quickly, so that the amount ofcompressed air required for this operation is limited. Y y

When the escapeof air from the pipe 48 by way of the restricted passage56 has eifected a predetermined reductionin the fluid pressure in thechamber 36 and the timing reservoir 3, the spring 43 becomes effectiveto return the valve piston element 34 to its seated position as shown inthe drawing, wherein the gasket 39 is held in engagement with the seatrib 4I) for outing off communication between the timing reservoir 3 andthe pipe 48, While the pipe is connected to atmosphere by way of thepassage 49, port 41, chamber 45 and passage 46.

As the pressure of air in the diaphragm chamber 8 of the drain valvedevice 2 is thus nally reduced to that of the atmosphere, the springs 2Band 26 again become effective to shift the valve I8-and vassociatedelements downwardly toward the position in which they are shown in thedrawing. While the double valve element I8 is thus moved from the seatI9 to the seat 28, it effects another discharge of accumulated waterfrom the chamber I2 as hereinbefore explained. The Various elements ofthe drain valve apparatusv are thus vreturned to the initial position,ready for the next cycle of operation. It will be understood that afterthe valve piston element 34 has been moved to the seat rib 40 by thespring 43, the pressure of air in timing reservoir 3 will again begradually built up by ilow of air from the reservoir l, as hereinbeforeexplained. After a predetermined interval, the air pressure acting onthe valve piston element overcomes the spring 43, whereupon theequipment once more becomes effective to actuate the drain valve device2 through the same operative cycle. The drain valve device thuscontinues to cycle regularly as long as sufficient air under pressure isavailable in the main res ervoir I.

From the foregoing'description it will be seen that the elementsrequired for construction of an automatic drain valve apparatus inaccordance with my invention are simple in design and relativelyinexpensive, and may be expected t0 operate through a long service lifewithout appreciable wear.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. In a drain valve equipment for discharging condensate accumulating ina receptacle for compressed air, the combination therewith of ranautomatic drain valve device having valve means responsive to variationsin fluid pressure in a chamber for ejecting water deposited in saidreceptacle, a timing reservoir having an always open but restrictedcommunication with said receptacle, and reciprocating valve meansoperative upon a predetermined increase in the pressure of air in saidtiming reservoir for establishing communication therefrom to saidchamber. 2. In a drain valve equipment for discharging condensateaccumulating in a receptacle for compressed air, the combinationtherewith of an automatic drain valve device having valve meansresponsive to variations in iluid pressure in a chamber for ejectingwater deposited in said-receptacle, a timing reservoir having an alwaysopen but restricted communication with said receptacle, a spring, andfluid pressure operated compressed air, the combination therewith of anautomatic drain valve device having valve means responsive to variationsin fluid pressure in a chamber for ejecting water deposited in saidreceptacle, a timing reservoir having an always open but restrictedcommunication with said receptacle, a pipe connected to said chamber,said pipe having a restricted atmospheric communication, and normallyclosed timing Valve means controlling communication between said timingreservoir and said pipe, said timing valve means being subject to thepressure of air in said timing reservoir and to a yieldable opposingforce.

4. In a drain valve equipment for discharging condensate accumulating ina receptacle for compressed air, the combination therewith of anautomatic drain valve device having valve means responsive to variationsin fluid pressure in a chamber for ejecting water deposited in saidreceptacle, means providing a communication from said chamber to theatmosphere, a timing reservoir always having restricted communicationwith said receptacle, and control means including a spring and a timingvalve element biased thereby toward seated position, said element beying operable upon each predetermined increase in pressure of air in saidtiming reservoir to establish communication therefrom to said chamberuntil timing reservoir pressure is reduced to a predetermined value.

5. In a drain valve equipment for discharging condensate accumulating ina receptacle for compressed air, the combination therewith of anautomatic drain valve device having valve means responsive to variationsin Iiuid pressure in a chamber for ejecting water deposited in saidreceptacle, a timing reservoir having a restricted inlet communicationwith said receptacle and a gravity ow drainage outlet, a pipe disposedbelow said timing reservoir and connected to said chamber in the drainvalve device, said pipe having a restricted atmospheric dischargecommunication, and a valve device operative alternately to establish andcut off communication from said timing reservoir inlet to said pipe.

WALTER B. KIRK.

